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    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
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<body>


    <body>

        <select id="1" type="select-multiple">
            <option value="volvo">Volvo</option>
            <!-- <option value="saab">Saab</option>
            <option value="opel">Opel</option>
            <option value="audi">Audi</option> -->
        </select>

        <script>
            var zaire = new Option(
                "Zaire",
                "zaire",
                "false",
                "false"
            )
            // 通过添加到option数组中，在Select元素中显示该选项

            var countries = document.getElementById("1");
            var optin = document.createElement("option");
            optin.value = "22";
            optin.innerHTML ="2"
            countries.appendChild(optin);
            
        </script>

    </body>




</body>

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